But the electrical grid can’t run off solar alone. In addition to the fact that it’s only expected to be 3 percent of generation by 2050, there is also the very basic problem that the sun only shines during the day, and we use electricity all the time.

Enter electrical storage.

The U.S. Department of Energy on Tuesday announced a round of new grants for research and development on solar plus storage — what the head of the solar industry trade association calls “the missing piece of the puzzle.”

Storage will help utilities manage the grid, lower costs, help ensure reliability during emergencies, and make the U.S. energy sector more self-sufficient, Rhone Resch, president of the Solar Energy Industries Association (SEIA) told reporters on a call Monday. But it’s not just altruism spurring the industry’s backing of storage. As Resch put it, “Innovation in storage will help drive solar.”

Solar needs storage, and storage is most useful for intermittent sources. This symbiosis is perhaps that’s why the new Energy Department initiative, the SHINES program (Sustainable and Holistic Integration of Energy Storage and Solar PV), seeks to combine the two.

Among Monday’s awardees is the forward-looking Austin Energy Company. The Texas utility has a mandate to get 55 percent of its power from renewable resources by 2025 — an earlier mandate of 30 percent by 2020 got updated when the company realized it was going to hit the goal well before the deadline. Currently, the company is projecting to get 51 percent of its power from renewables by the end of the year.

But storage is “really the game changer,” Austin Energy’s Karl Popham told ThinkProgress.

Up to now, battery storage has been cost-prohibitive for most utilities, which is partly why research and development is so important. The new initiative is shooting to make solar plus storage cost 14 cents per kilowatt hour — a fairly average consumer price. But it’s also new that utilities have the technology to track the grid closely enough make all this possible. More advanced inverters — the component that changes electricity from the kind that runs from pole to pole to the kind that powers your hairdryer — will allow grid operators to go from generation to storage and back again, all with remote software.

“We want renewables to be just as counted on and dispatchable and reliable as any fossil fuel generation,” Popham said.

Austin Energy and its partners received $4.3 million — and will contribute just a bit more than that — to carry out a pilot program including solar, battery storage, and smart inverter technologies. The three-year program will add battery storage to a community solar project already under development, attach another battery to existing rooftop solar, and attempt to figure out the best way to integrate solar and storage for utility, commercial, and residential customers.

Popham said there would be “a lot of learning” in the process — which is the point of the grant. SHINES is part of the Energy Department’s Grid Modernization plans.

“We’re excited. We’re ready to roll up our sleeves,” Popham said.

But as utilities and grid operators look to meet the goals of the Clean Power Plan — and face the economic realities of lowering costs for renewables and growing awareness of the pollution associated with fossil fuels — they are also going to have to figure out how to best use these new technologies.

The company expects to install batteries for the program sometime in 2017.